Which is the transfer of genes from one population to another?
gene flow
genetic drift
gene mutation
genetic selection

Question 11 which of the following personal health practices should a person follow to reduce the risk of skin cancer? avoid staying outdoors when the sun is strongest. consume antibiotics to prevent bacterial attacks. wash hands frequently to maintain proper hygiene. have a balanced diet and exercise regularly. question 12 a student wants to compare how easily a metal and a plastic spoon of the same temperature can transfer thermal energy. which of the following activities should the student perform? measure the effort required to bend each spoon. place an ice cube on each spoon and record the rate of melting of the cubes. place the spoons at room temperature and record the change in temperature of each. measure the change in weight of the spoons after placing them in the freezer for a few minutes. question 13 the characteristics of certain cell divisions are described in the following table. cell division characteristics characteristic description 1 forms diploid cells 2 creates sex cells, or gametes which type(s) of cell division do the two characteristics represent? both characteristics represent meiosis. both characteristics represent mitosis. characteristic 1 represents meiosis and characteristic 2 represents mitosis. characteristic 1 represents mitosis and characteristic 2 represents meiosis. question 14 which of the following adaptations in wooly mammoths could have best prevented their extinction? shedding of fur darker color of fur growth of an extra layer of fur increase in the thickness of fur question 15 maria and ben are both suffering from a hereditary disease, as described in the following table. description of disease patient description maria blood cells get stuck in blood vessels, causing painful attacks ben hemoglobin is abnormal due to curved shape of red blood cells which disease(s) are maria and ben suffering from? both are suffering from type 1 diabetes. both are suffering from sickle cell anemia. maria is suffering from sickle cell anemia and ben from type 1 diabetes. maria is suffering from type 1 diabetes and ben from sickle cell anemia. question 16 which of the following icons is used to represent a female carrier of a disease? a half-filled circle a half-filled square a completely filled circle a completely filled square question 17 joe sowed seeds of a plant in two different types of soil in separate pots. she added the same amount of fertilizer to the pots. she then placed the pots in the sun and recorded their growth after four days. what is the independent variable in the study? duration of growth amount of fertilizer growth of seeds type of soil question 18 philip has curly hair and his sister has straight hair. which of the following explains why philip and his sister have different hair types? both children received the same hair coding gene from their mother. both children received the same hair coding gene from their father. their mother was exposed to different environments before their births. the children each received different genes from their parents. question 19 which statement is most likely correct about species which cannot adapt? they become extinct. their immunity increases. their population increases. they produce more offspring. question 20 four animals live in the arctic. their characteristics are described in the following table. animal characteristics a long tail b small feet c black fur d white skin which animal is least likely to be captured by its enemies? animal a animal b animal c animal d

Which sentence is an example of a strong conclusion to an autobiography? a. i stayed after school three days in a row to practice onstage in the auditorium. b. i knew i would have to practice all week to memorize my dance for the recital. c. after the recital was over, i knew practicing was worth it, and i was looking forward to my next big challenge. d. on opening night, i danced in front of a packed auditorium.

Rease is an enzyme used by plants to break down urea (a nitrogen-containing compound) into carbon dioxide and ammonia. urease urea > > > carbon dioxide and ammonia ammonia is broken down by plants into a nitrogen source plants need to grow. thus, plants could not use urea as a nitrogen source unless it was first converted to ammonia. in soybean plants there are two different kinds of urease, one produced in the seeds and the other produced in the leaves of the plant. three types of soybean plants were used in a set of experiments: normal soybeans and two mutant strains, one lacking the urease in the seeds only (strain 1) and one lacking urease in the leaves only (strain 2). experiment 1 separate areas in a field were planted with normal, strain 1, and strain 2 soybeans. all types of soybeans appeared to grow, flower, and produce seeds equally well. there were no externally detectable differences among the strains. experiment 2 small pieces of plant leaves of equal weight were obtained from each type of soybean plant and separately placed on media in culture dishes. tissue growing in this way will become an unorganized clump of cells referred to as callus. to provide a controlled nitrogen source, half the tissue samples of each type were placed on media containing urea, and the other half of the samples were placed on media containing ammonia. after 30 days, the weight gain for each of the callus samples was determined. results are shown in the table below.